/****************************************************************************
 **
 ** Copyright (C) 2016 The Qt Company Ltd.
 ** Copyright (C) 2016 Klar?lvdalens Datakonsult AB, a KDAB Group company, info@kdab.com, author Milian Wolff <milian.wolff@kdab.com>
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the QtWebChannel module of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:LGPL$
 ** Commercial License Usage
 ** Licensees holding valid commercial Qt licenses may use this file in
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
 ** and conditions see https://www.qt.io/terms-conditions. For further
 ** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Lesser General Public License Usage
 ** Alternatively, this file may be used under the terms of the GNU Lesser
 ** General Public License version 3 as published by the Free Software
 ** Foundation and appearing in the file LICENSE.LGPL3 included in the
 ** packaging of this file. Please review the following information to
 ** ensure the GNU Lesser General Public License version 3 requirements
 ** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
 **
 ** GNU General Public License Usage
 ** Alternatively, this file may be used under the terms of the GNU
 ** General Public License version 2.0 or (at your option) the GNU General
 ** Public license version 3 or any later version approved by the KDE Free
 ** Qt Foundation. The licenses are as published by the Free Software
 ** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
 ** included in the packaging of this file. Please review the following
 ** information to ensure the GNU General Public License requirements will
 ** be met: https://www.gnu.org/licenses/gpl-2.0.html and
 ** https://www.gnu.org/licenses/gpl-3.0.html.
 **
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/

"use strict";

var QWebChannelMessageTypes = {
  signal: 1,
  propertyUpdate: 2,
  init: 3,
  idle: 4,
  debug: 5,
  invokeMethod: 6,
  connectToSignal: 7,
  disconnectFromSignal: 8,
  setProperty: 9,
  response: 10,
  heartbeat: 11 // 新增心跳类型
};

var QWebChannel = function (transport, initCallback) {
  if (typeof transport !== "object" || typeof transport.send !== "function") {
    console.error("The QWebChannel expects a transport object with a send function and onmessage callback property." +
        " Given is: transport: " + typeof (transport) + ", transport.send: " + typeof (transport.send));
    return;
  }

  var channel = this;
  this.transport = transport;

  this.send = function (data) {
    if (typeof (data) !== "string") {
      data = JSON.stringify(data);
    }
    channel.transport.send(data);
  }

  this.transport.onmessage = function (message) {
    var data = message.data;
    if (typeof data === "string") {
      data = JSON.parse(data);
    }
    switch (data.type) {
      case QWebChannelMessageTypes.signal:
        channel.handleSignal(data);
        break;
      case QWebChannelMessageTypes.response:
        channel.handleResponse(data);
        break;
      case QWebChannelMessageTypes.propertyUpdate:
        channel.handlePropertyUpdate(data);
        break;
      case QWebChannelMessageTypes.heartbeat:
        // 处理心跳消息
        break;
      default:
        console.error("invalid message received:", message.data);
        break;
    }
  }

  this.execCallbacks = {};
  this.execId = 0;
  this.exec = function (data, callback) {
    if (!callback) {
      // if no callback is given, send directly
      channel.send(data);
      return;
    }
    if (channel.execId === Number.MAX_VALUE) {
      // wrap
      channel.execId = Number.MIN_VALUE;
    }
    if (data.hasOwnProperty("id")) {
      console.error("Cannot exec message with property id: " + JSON.stringify(data));
      return;
    }
    data.id = channel.execId++;
    channel.execCallbacks[data.id] = callback;
    channel.send(data);
  };

  this.objects = {};

  this.handleSignal = function (message) {
    var object = channel.objects[message.object];
    if (object) {
      object.signalEmitted(message.signal, message.args);
    } else {
      console.warn("Unhandled signal: " + message.object + "::" + message.signal);
    }
  }

  this.handleResponse = function (message) {
    if (!message.hasOwnProperty("id")) {
      console.error("Invalid response message received: ", JSON.stringify(message));
      return;
    }
    channel.execCallbacks[message.id](message.data);
    delete channel.execCallbacks[message.id];
  }

  this.handlePropertyUpdate = function (message) {
    for (var i in message.data) {
      var data = message.data[i];
      var object = channel.objects[data.object];
      if (object) {
        object.propertyUpdate(data.signals, data.properties);
      } else {
        console.warn("Unhandled property update: " + data.object + "::" + data.signal);
      }
    }
    channel.exec({ type: QWebChannelMessageTypes.idle });
  }

  this.debug = function (message) {
    channel.send({ type: QWebChannelMessageTypes.debug, data: message });
  };

  // 心跳间隔时间，单位毫秒（例如10秒）
  var heartbeatInterval = 20000;

  // 定义发送心跳消息的函数
  function sendHeartbeat() {
    channel.send({ type: QWebChannelMessageTypes.heartbeat });
  }

  // 启动心跳定时器
  setInterval(sendHeartbeat, heartbeatInterval);

  channel.exec({ type: QWebChannelMessageTypes.init }, function (data) {
    for (var objectName in data) {
      var object = new QObject(objectName, data[objectName], channel);
    }
    // now unwrap properties, which might reference other registered objects
    for (var objectName in channel.objects) {
      channel.objects[objectName].unwrapProperties();
    }
    if (initCallback) {
      initCallback(channel);
    }
    channel.exec({ type: QWebChannelMessageTypes.idle });
  });
};

function QObject(name, data, webChannel) {
  this.__id__ = name;
  webChannel.objects[name] = this;

  // List of callbacks that get invoked upon signal emission
  this.__objectSignals__ = {};

  // Cache of all properties, updated when a notify signal is emitted
  this.__propertyCache__ = {};

  var object = this;

  // ----------------------------------------------------------------------

  this.unwrapQObject = function (response) {
    if (response instanceof Array) {
      // support list of objects
      var ret = new Array(response.length);
      for (var i = 0; i < response.length; ++i) {
        ret[i] = object.unwrapQObject(response[i]);
      }
      return ret;
    }
    if (!response
        || !response["__QObject*__"]
        || response.id === undefined) {
      return response;
    }

    var objectId = response.id;
    if (webChannel.objects[objectId])
      return webChannel.objects[objectId];

    if (!response.data) {
      console.error("Cannot unwrap unknown QObject " + objectId + " without data.");
      return;
    }

    var qObject = new QObject(objectId, response.data, webChannel);
    qObject.destroyed.connect(function () {
      if (webChannel.objects[objectId] === qObject) {
        delete webChannel.objects[objectId];
        // reset the now deleted QObject to an empty {} object
        // just assigning {} though would not have the desired effect, but the
        // below also ensures all external references will see the empty map
        // NOTE: this detour is necessary to workaround QTBUG-40021
        var propertyNames = [];
        for (var propertyName in qObject) {
          propertyNames.push(propertyName);
        }
        for (var idx in propertyNames) {
          delete qObject[propertyNames[idx]];
        }
      }
    });
    // here we are already initialized, and thus must directly unwrap the properties
    qObject.unwrapProperties();
    return qObject;
  }

  this.unwrapProperties = function () {
    for (var propertyIdx in object.__propertyCache__) {
      object.__propertyCache__[propertyIdx] = object.unwrapQObject(object.__propertyCache__[propertyIdx]);
    }
  }

  function addSignal(signalData, isPropertyNotifySignal) {
    var signalName = signalData[0];
    var signalIndex = signalData[1];
    object[signalName] = {
      connect: function (callback) {
        if (typeof (callback) !== "function") {
          console.error("Bad callback given to connect to signal " + signalName);
          return;
        }

        object.__objectSignals__[signalIndex].push(callback);

        if (!isPropertyNotifySignal && object.__objectSignals__[signalIndex].length === 1) {
          // only required for "pure" signals, handled separately for properties
          webChannel.exec({
            type: QWebChannelMessageTypes.connectToSignal,
            object: object.__id__,
            signal: signalIndex
          });
        }
      },
      disconnect: function (callback) {
        if (typeof (callback) !== "function") {
          console.error("Bad callback given to disconnect from signal " + signalName);
          return;
        }
        var idx = object.__objectSignals__[signalIndex].indexOf(callback);
        if (idx === -1) {
          console.error("Cannot find connection of signal " + signalName + " to " + callback.name);
          return;
        }
        object.__objectSignals__[signalIndex].splice(idx, 1);

        if (!isPropertyNotifySignal && object.__objectSignals__[signalIndex].length === 0) {
          // only required for "pure" signals, handled separately for properties
          webChannel.exec({
            type: QWebChannelMessageTypes.disconnectFromSignal,
            object: object.__id__,
            signal: signalIndex
          });
        }
      }
    };
    object.__objectSignals__[signalIndex] = [];
  }

  function invokeSignalCallbacks(signalName, signalArgs) {
    var connections = object.__objectSignals__[signalName];
    for (var i in connections) {
      connections[i].apply(connections[i], signalArgs);
    }
  }

  this.propertyUpdate = function (signals, propertyMap) {
    // update property cache
    for (var propertyIndex in propertyMap) {
      var propertyValue = propertyMap[propertyIndex];
      object.__propertyCache__[propertyIndex] = propertyValue;
    }

    for (var i in signals) {
      invokeSignalCallbacks(signals[i], []);
    }
  }

  this.signalEmitted = function (signalName, signalArgs) {
    invokeSignalCallbacks(signalName, signalArgs);
  }

  function addMethod(methodData) {
    var methodName = methodData[0];
    var methodIdx = methodData[1];
    object[methodName] = function () {
      var args = [];
      var callback;
      for (var i = 0; i < arguments.length; i++) {
        if (typeof arguments[i] === "function")
          callback = arguments[i];
        else
          args.push(arguments[i]);
      }
      webChannel.exec({
        type: QWebChannelMessageTypes.invokeMethod,
        object: object.__id__,
        method: methodIdx,
        args: args
      }, function (response) {
        if (response !== undefined) {
          var result = object.unwrapQObject(response);
          if (callback) {
            (callback)(result);
          }
        }
      });
    };
  }

  function bindGetterSetter(propertyInfo) {
    var propertyIndex = propertyInfo[0];
    var propertyName = propertyInfo[1];

    object.__propertyCache__[propertyIndex] = propertyInfo[2];

    Object.defineProperty(object, propertyName, {
      configurable: true,
      get: function () {
        var propertyValue = object.__propertyCache__[propertyIndex];
        if (propertyValue === undefined) {
          console.error("Undefined value in property cache for property \"" + propertyName + "\" in object " + object.__id__);
        }
        return propertyValue;
      },
      set: function (value) {
        if (value === undefined) {
          console.error("Property setter for " + propertyName + " called with undefined value!");
          return;
        }
        object.__propertyCache__[propertyIndex] = value;
        webChannel.exec({
          type: QWebChannelMessageTypes.setProperty,
          object: object.__id__,
          property: propertyIndex,
          value: value
        });
      }
    });

    addSignal([propertyInfo[3], propertyInfo[0]], true);
  }

  data.methods.forEach(addMethod);
  data.properties.forEach(bindGetterSetter);
  data.signals.forEach(function (signal) { addSignal(signal, false); });
  for (var name in data.enums) {
    object[name] = data.enums[name];
  }
}

//注释掉这块
//required for use with nodejs
// if (typeof module === 'object') {
//     module.exports = {
//         QWebChannel: QWebChannel
//     };
// }

//改成这种导出方式
export default {
  QWebChannel
};
